Alkali-metal cyanide production



Jan. 1, 1929.,

H. KIPPER ALKALT METAL CYANIDE PRODUCTION Fi 1 ed March 1, 1926 [nuanfov Herman BKK 93% 5% (Worms Patented Jan. 1, 1929.

UNITED STATES HERMAN B. KIPIPER, OF MUSKEGON, MICHIGAN.

ALKALI-METAL CYANIDE PRODUCTION.

Application filed March 1, 1926. Serial 110 91.590.

This invention relates to novel apparatus for the production of cyanide or similar compounds. It is well known and understood that if nitrogen or air which contains nitro- 6 gen is passed over sodium carbonate, or analogous carbonates, carbon and iron mixed together, at a high temperature above 900 to 1000 degrees Centigrade, the nitrogen will combine with the carbon and the element of the sodium so as to produce sodium cyanide.

And the same underlying principle of chemical action may be utilized to produce other cyanides or analogous compounds such as potassium cyanide and the like.

While knowledge of these reactions has been known for a great inany years the commercial production of such cyani'de'conn poundshas only recently been attained.

' Many forms of apparatushave been tried and attempted for this purpose and I have secured a Patent 1,322,026, granted November 18,1919, on an apparatus which, while amarked improvement over prior apparatus for the same purpose, is not sufliciently perfected and com-' plete for the commercial production of the desired cyanides. After extensive experiinents and trials I have produced the apparatus shown in the accompanying drawing and described in the following description with which commercial quantity product on and a. very rapid production of the cyanide desired may be had. In these drawings,

Fig. 1 is a longitudinal vertical section through a part of said apparatus.

Fig. 2 is a transverse vertical ,sectron through the receptacle or container in which the reactive ingredients used for the production of'the cyanide are received.

Fig. 3 is a plan view ofthe' complete apparatus, and

Fig. 1. 's a fragmentary vertical sect on through one element of the apparatus 'whlch is used for the production of carbon monoxide. 7

Like reference characters refer to like parts in the several figures of the drawing; In the construction'of the apparatus whlch Ihave provided, a relatively large cylinder 1 is used, shown as positigned horizontally, at the upper side of which is an inlet pipe 2 normally closed by a cover 2 and having mounted below its upper end a door 3 which, in the position shown in Fig. 1, is located across the pipe 2 and serves as a bottom member of a hopper supporting the materials whlch are to be introduced into the cylinder when the .spiders.

same are put in the pipe 2, cover 2* being removed. Then after cover 2 is replaced the door 3 may be turned so as to dump the ma-' very high temperature rapidly decompose in the presence of oxygen or carbon dioxide.

outwardly by a The ends of the cylindrical container 1 are closed by end plates 7. A sleeve 8 passes through each of the end plates 7 and is rotatably mounted therein, each at its inner end having a member 9 secured thereto between which a plurality of beveled scraper bars 10 are located being secured at their ends to the members 9 and reinforced and strengthened between their ends by rings 11, shown. A shaft 12 passes through and is rotatably mounted in the sleeves 8 and has bearings at its ends at the upper ends of posts 18 and 13, as shown in Fig. 1 A number of spiders 14 having radiating arms are fixed at spaced apart distances to the shaft 12 and a secondseries of beveled bars '15 are attached to and extend between the arms of said Shaft 12 is driven by means of a pulley 16 attached to the shaft between the posts 13 and 13 at one end of the cylindrical cated in the same .vertical planes with the other larger sprocket wheels 20 attached to the outer ends of said sleeves 8, sprocket chains 20 passing around the wheels. The shaft 18.niay be driven in any suitable manner at low speed so that the sleeves 8 turn very slowly, usually not more than 1 R. P. M.

Two pipes 21 and 22 are connected with the cylinder 1 adjacent its opposite ends. The pipe 21 leads from said cylinder to a scrubber 23 which may be of any well known and conventional construction similar to the scrubhers "used in purifying and washing gases, as

, need not be entered into. As will later appear, carbon monoxide gas passes from the cylinder 1 through the pipe 21 to the scrubber and these gases are freed therein from any cyanide or other dust, the carbon monoxide V gas passing from the scrubber through a. pipe 33 and 34 which come together and are joined.

24 to the air .preheater system in whiclrthe burning of the carbon monoxide is utilized for the preheating of air.

Y The pipe 24 is connected with two pipes 25 and 26 which extend oppositely to each other, one leading to a stove 27 and the other to a similar stove 28. At the junction of the pipes24, 25 and 26, a control damper 29 is positioned which may be moved to two different positions, in one of which the gases passing through the pipe 24 may be led to the stove 27 and in the other of which said gases may be led to the stove 28.' Three blowers 30, 31 and 32 driven by small electric motors are associated with the pipes 24, 25 and 26,

I as shown in Fig. 3, for blowing air into said pipes. The stoves 27 and 28 have outlet pipes and at their junctions are equipped with a second damper 35, which turned to different positions, directs the products of combustion from a stove which is burning the carbon monoxide gas to the stack 36 and directs the air which is heated by passing through the other stove so as to pass through an outlet pipe 37 to a gas producer 38, shown in,

Fig. 4.

Itis to be understood that the stove 28, shown in Fig. 3, has previously been heated to. very high degree of temperature and that the air forced therethrough by the blower 32 in assing through said stove is raised to a big 1 degree of temperature. The stove 27 in the meantime is being heated to a highdegree of temperature by the burning carbon monoxide gas. When stove 27 has reached I its proper temperature and stove 28 has become cooled, the positions of the dampers 29 and 35 are changed so that air is blown through the stove 27 and heated therein as it passes to the gas producer 38 and the stove 28 is reheated by burning carbon monoxide therein.

The preheated air which passes through the pipe 37 to the gas producer 38 serves to combine with carbon located within the gas producer 38 and which is introduced therein through an upperinlet neck 39, in which a gate 41 is movably mounted and which may be operated to drop coke or other similar carbon material into the gas producer 38, this gate closingthe inlet 39 when in the position shown in Fig. 4. The coke or other carbon 41 is shown at the lower end of the gas producer and the pipe 37 carrying the preheated air theremto enters at the ottom of said gas producer. Carbon monoxide mixed with nitrogen is produced and by reason of the high degree oftemperature to which the air has been preheated the carbon monoxide and nitrogen which passes through the pipe 22 to the cylinder 1 are at a very high degree of temperature, usually between 1000 and 1800 degrees centigrade.

The operation of this apparatus may be dcscribed as follows: g The reaction material in finally divided state, such as sodium carbonate, carbon and iron, having been introduced into the cylinder 1 through the inlet pipe 2 and with the shaft 12 and connected bars 15 rotating at approximately 300 R. P. M. is continually stirred and agitated and is beaten and ground and maintained in its finally divided condidegrees centigrade, is brought into very intimate relation with the reacting material and there is produced by'the reaction, sodium cyanide and additionalcarbon'monoxide, the sodium carbonate releasing its atoms of oxygen and combining with nitrogen to make the cyanide, while the oxygen released combines with the carbon of the reacting material to make carbon monoxide. The cyanide produced falls into the receiving chamber 5 filled with nitrogen, and is there cooled, being removed by the conveyer 6 after it has properly cooled, while the carbon monoxide produced is carried through the pipe 21 ,tothe scrubber 2 3 and is then burned to heat the stoves 27 and 28, as previously described.

The reactions which take place in the container 1 do not produce heat but on the contrary require the presence of a large quantity of heat which is absorbed during the progress of the reactions.- It is for this reason that the air which passes through the gas producer 38 is reheated to very high degree .of tempera- .tureso that all heat possible which can 'be provided and carried into the cylinder 1 is obtained, advantage being taken of the fact that the large production of carbon monoxide during the reactions formsa fuel which may be burned to provide for preheating the air as described. The continuous grinding, heating and dissemination of the reactive mate rials within the cylinder maintains the same in a more or less pulverized condition so that thehghly heated carbon monoxide is brought into intimate relation with all of the particles of the reactive mixture causing the reactions to take place very rapidly. movement of'the scraper bars 10 keeps the inner sides of the container free of any materials which may tend to cake and buildup thereon and also serves ito help maintain the reactive material in bro en condition and so produced in the Kraft processot digesting wood to pulp. This is a feature of commercial advantage though any proper carbon ma terial may be used in so far as the reactions required in this process are concerned.

This construction of apparatus serves to rapidly 'and eltectively produce cyanide compounds and such production is made commercial by the apparatus shown and described. For instance the use of regenerator stoves illustrated in the drawings and described in the description for heating the air going to' the gas productor can be supplanted by a recuperator having the same effect, this being a well known construction for heating air from exhaust fuel given oft by this type of apparatus. And in many other ways departure can be made from the specific and exact structure shown and described so long as it is within the terms of the claims of the invention. The actual temperature ot'opera; tion, that is, the temperature maintained in cylinder-l to bring about the reaction in ques tion, lies between 700 and 1000 degrees centigrade. The character of the carbon, aswell as the character of the alkali salts used, ap-

' pear to determine the actual requisite temperature. For instance a mixture of potassium and sodium-salts would appear to require a lower operating temperature and when either of these salts .is used alone. The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within the scope of said claims. i

I claim:

1. The herein described process of alkali maintaining it in finely divided and disseminated condition and also continuously slowly scraping the inner walls of said receptacle to keep the walls free of said material and continuously subjecting said material to the action of highlyheated reactive gases whereby alkali'cyanides are rapidly produced.

2. The herein described process of alkali cyanide production which consists, in placing alkali forniing metal salts and catalytic ma,- terials in a closed receptacle having-an inlet and outlet, continually and with great rapidity stirring said salts and catalytic materials and maintaining them in finely divided and disseminated condltlon by means of rapslowly scrapingthe innerwalls of the reacting. vessel from'niaterial deposited thereon, said the materials contained in the reacting vessel to the action of nitrogen-gas heated above 700 centigrade, whereby alkali cyanides are produced with great rapidity. a 3. The herein described process of producing sodium cyanide which consists, in placin a mixture of sodium carbonate, carbon an an iron catalyst within a closed container, stirring, beating and grinding and disseminating said materials very rapidly by means of revolving metal parts rotating at high 'idly moving metal parts which act toalso beat and grind the materials, continuously scraping being accomplished by slowly mov mg metal parts, and continuously SL1b]8Ct1I1g speed,.and also scraping the inner Walls of the reaction receptacle from deposit-s collecting thereon by slowly moving metal scraper bars moving over the inner surface of said container and subjecting said mixture of materials to the action of highly heated nitrogen gas to thereby produce sodium cyanide.

4. The herein described p-roces s of producmg sodium cyanide which consists, in placin a; mixture of sodium carbonate, carbon an an iron catalyst within a closed container, beating, grinding, stirring and disseminating said materials by means of rapidly moving. metal parts which stir and grind the material .andbeat it'as thematerial strikes against said parts thereby maintaining the same in very finely divided and disseminated condition, slowly scraping the inner Walls of the reaction container to maintain it free of deposits tending to collect thereon, and-continuously subjecting said material to the action of nitrogen and carbon monoxide heated to a high degree of temperature in excess of 700 degrees centigrade. y

In testimony whereof I alfix my signature.

HERMAN B. KIPPER, 

